Automotive-vehicle ignition-circuit system



Jan. 24, 1928. 1,657,003

G. L. CRAGG AUTOMOTIVE VEHICLE IGNITION CIRCUIT SYSTEM Filed March 17. 1927 AZ 66 5% Z0 22 Patented Jan. 24, 1928 1,657,003 UNITED STATES. PATENT OFFICE.

GEORGE L. CRAGG, OF CHICAGO, ILLINOIS, ASSIGNOR BRONSON, MICHIGAN.

T0 HARRY nunonems'or AUTOMOTIVE-VEHICLE IGNITION-CIRCUIT SYSTEM. 4

Application and March 17, 1927. Serial No. 17 ,233.

such a system which employs an inducing circuit that contains a primary winding anda second circuit which contains a spark plug or other gas igniting element and a Winding that is in secondary relation to said primary winding. The primary or inducing circuit usually contains a battery'or' other sources of direct current and a switch for opening and closing this circuit, the secondary or induced circuit that contains the spark plug or other gas igniting element being efi'ective for its purpose when the primary circuit is closed. When the ignition system is employed in connection with the internal combustion hydrocarbon engine contained in the power plant of an automotive vehicle, it is the practice to provide a lock, usually key controlled, for locking the aforesaid switch in open adjustment to prevent unauthorized use of theautomotive vehicle. The purpose of the lock, in prior structures, may be defeated by injectlng current conducting fluid, such as mercury, into the switch chamber, the mercury acting as a jumper to connect the contacts of the switch in the primary circuit that are locked apart In carrying out my invent1on,I employ a guarding contact which is not employed in any of the manually effected adjustments of the switch but which is brought intoelectrical connection with the switch when mercury is injected into the switch chamber so that when the mercury serves to close the switch contacts, it also establishes a circuit which will render the ignition equipment ino er'ativ'e whereby the intended purpose of t e mercury is defeated. I

- In the preferred embodiment of the invention, the normally idle or guarding contact is included in a normally open shunt'of the battery, this shunt being completed when the mercury is employed, as stated. In order to avoid fire that might result from the short 'circuiting of the battery by mercury, I introduce a protecting device in circuitwiththe guarding contact that prevents the full fiow of thebattery current, this protecting device being desirably a fuse which is blown when the short circuit is established to pre-- vent any flow of the battery current.

i I will explain my invention more fully by reference to which Fig. 1 of an induction coil and a lock controlled switch in assembly therewith; Fig. 2 is a sectional view of a part of the structure taken on line r2 -2 of Fig. 3'; Fig. 3 is a sectional view of a part of the structure taken on line 3-3 of Fig. 1; andFig. 4 is adiathe accompanying drawing in gram of one circuit arrangement.

I have illustrated a hollow current gonducting element including a winding 1 constituting'the primary of an induction coil that is employed in a circuit serving to procombustion engine. Another winding 2 is illustrated which, in this instance, is secondary to the winding 1, this secondary winding being shown as being surrounded by the primary winding. The primary winding has one terminal grounded through a c1rcu1t interrupter 3 whose contacts are shunted by a condenser 4:. The other ter minal of the primary winding is grounded through a battery 5. The secondary windmg 2 also has one terminal grounded through the circuit interrupter 3, the other terminal of the winding 2 being connected with the revolving arm 6 of a distributor whose Waiting contacts 7 are successively engaged by said arm,these waiting contacts being connected with the electrodes 8 of spark plugs or other gas igniting elements that are contained in the various cylinders of the internal combustion engine, indicated it 9, that is equipped with the ignition sys- .em f

The windings 1 and 2 are tubular, the bore of the inner winding having a tubular lining 10 of insulation.

is a longitudinal sectional viewduce sparks in the cylinders of an internal A magnetizable; core 11 1s showndisposed within said lining,

A porcelain cap;15 assem-- A terminal connector 13 is provided for coni necting the distributor arm 6 with the secondary 2, this terminal connector being suitably assembled within the central portion of the cap 15. The rear end wall of the cap portion 12 carries binding posts 17, 18 and 19' which have circuit connections, as diagrammatically indicated in Fig. 4.

A. lock casing 20 is provided at the front end of the structure, this casing being closely surrounded by the cylindrical portion inner lining that is constituted of a disc 23. The end wall 14 is provided with sleeve rivet extensions 24 which clamp the disc 23 to the opposite sidesof said shell.

end wall and serve as means for effectively receiving the stems of the binding screws 21. A. locking guard, preferably in the form of a shell 25, has a flange 26 at its outer end which is rigidly clamped between the disc 23 and the wall portion 14. The shell projects inwardly into the lock easing into close proximity to the rear wall 27 of this casing. A, tumbler barrel 28 is mounted to turn in the shell 25, this tumbler barrel carrying tumblers 29 which are receivable at their ends in slots 30 that are formed 111 These tumblers are operable by the tumbler barrel, to be withdrawn from said slots when the key is inserted. When the, tumblers are withdrawn, the tumbler barrel may be turned to a position in which the primary circuit may be either opened or closed, as will more fully appear. When this circuit is opened, the key may be withdrawn to permit the tumblers to enter said slots, the tumblers then serving to lock the primary circuit in open adjustment, as will more fully appear.

The switching mechanism illustrated is disposed within a cap 32 of insulation, this cap having a rearwardly extending skirt portion 33 which surrounds the front end of the core 11 and a forwardly extending skirt portion 34 which surrounds the switching mechanism, there being a common wall 35 of the cap 32 which is between the two skirts 33 and 34 and from which these skirts project in opposite directions, the rear face of this wall 35 being in engagement with the front end of the core 11. The space surrounding the cap 32 is suitably occupied with a filling material of insulation as indicated at 36, in accordance with common practice. The switching mechanism illustrated is inclusive of two metallic springs 39 whereby these contacts are pressed inwardly toward each other. These springs are contained within spring-*barrelsAO that: are in spaced apart relation,- these spring barrels Ybeing rigidly securedto the .contact carrier cap.

41 which is inserted within the cap 32 and is surrounded by the front skirt 34 of this The carrier 41 is of insulation and is formed with a lateral groove 42 which receives a rib 43 that projects inwardly from the cap skirt 34 whereby said contact carrier is. held from rotation. ,Said contact carrier is in the form of a ring having a cylindrical bore which receives another contact carrier 44, the latter contact carrier being cylindrical and rotatable within the contact carrier 41. A contacting bar is carried by the contact carrier 44 and extends diametrically therethrough. The contacts 37, 38 and 45 are arranged in the same zone and in a plane perpendicular or transverse to the common axis of the windings 1 and 2, the contacts 37 and 38 being thus radially disposed. When the contact carrier 44 is turned in one position, its contacting bar 45 is out of engagement with said contacts .which are then received within recesses 46 formed in opposite sides of the carrier 44. The ignition circuit is then opened. When the latter contact carrier is reversely positioned, its contacting bar 45 engages both contacts whereby the ignition circuit is closed. The key 31 is adapted to place the contact carrier 44 in either an ignition circuit opening position or an ignition circuit closing position. To this end, the tumbler barrel 29 has an oblong inner extension 47 which is receivable within an oblong slot 48 which is formed in the enlarged front end of the carrier 44, the front enlargement of this carrier being bottomed against the carrier 41 so that the rearward movement ofthe carrier 44 is prevented, the forward movement of this carrier 44 being prevented by being in engagement with the lock shell 25. Assuming that the ignition circuit is open and is to be closed, the key is inserted to withdraw the tumblers 29 from the slots 30 whereafter the tumbler barrel is turned to bring the contacting bar 45 into engagement with the contacts 37 and 38. When the ignition circuit is again to be opened, the tumbler barrel is turned by the key to bring the tumblers into register with the slots 30 whereafter the key is withdrawn to permit the tumblers to enter said slots, the contacting bar 45 being now out of engagement with the contacts-37, 38. The arrangement of the lock controlled mechanism,'thus far specifically described in connection with the drawing, is covered by claims contained in my co-pending application, Serial No. 169,280, filed'February 18, 1927.

In accordance with my present invention, a contact or terminal 49 is associated with the switching mechanism, being contained. in

the same caslng therewith but normally takingno part in effecting any circuit changes.

This contact or terminal is shown in the form of a metallic screw, Fig. 3, which is 1 inserted intol the contact carrier 41 from the rear side of this carrier. The conducting wire 51 connects the contact or terminal 49 with the grounded pole of the battery 5. 11f a thiefishould drill an opening into. the

space between the contactcari'ier 41 and the rearwall of the switch chamber for the purpose of passing mercury into this spaceand should force mercury into this chamber for the purpose of connecting the contacts 37 and 38 when the contacting bar is locked out of engagement with these contacts, the mercury will connect the terminal 49 with both of these contacts thereby groundingthe primary coil 1 and short circuiting the battery 5, the intended purpose of the inserted mercury being thus defeated. A device for preventing full flow of the battery current is included in circuit with the terminal 49 and source of current 5, this device being preferably in the form of a use 52 that is included in the main circuit of the battery and which will blow when the battery is shortL-circuited to prevent any fiow of batteryacurrent. This fuse is shown as being connected between the battery and the switching mechanism contact 38, but may be elsewhere in the main circuit, and is of a limited capacity enabling it to be ruptured when the guarding terminal 49 and contact 38 are connected by current conducting fluid o that the battery then becomes operatively dissociated from the ignition circuit. In the preferred embodiment of the invention, the

casing which encloses the switching mechanism is of insulation whereby the guarding terminal or contact 49 and the various elements of the switch rely for their electrical association upon wiring though the invention is not to be thus restricted. In the preferred embodiment of the invention, however, the switch casing is electrically isolated, a result which is preferably accomplished by making it of insulating material.

Changes may be made without departing from the invention.

Having thus described my invention, I claim:

1. The combination with an ignition circuit for an internal combustion engine, this circuit containing a source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make said circuit ef fective and, by their separation, to make said circuit ineffective; an electrically isolated casing enclosing said switching mechan sm, said switching mechanism being provided with lock controlled means for effectin its operation from the'exterior of the casing;

and a guarding terminal normally having no efiective electrical connection within the casing with the contacts of the switching mechanism when the switch is open but excuit inefl'ective when this guarding terminal is connected with said switchingmechanism by current conducting fluid admitted to the casing.-

2. The combination with an ignition cir is cuit for an internal combustion engine, this circuit containing-a source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make said circuit effective and, by their separation, to make said circuit ineffective; an electrically isolated casing e11- closing said switching mechanism, said switching mechanism beine nrovided with lock controlled means for eflfecting its operation from the exterior of thecasing; and a guarding terminal normally having no effective electrical "connection within the casing with the contacts of the switching mechanism but exposed for contact with current to conducting fluid admitted into the casing to connect it with a contact of the switching mechanism, said guarding terminal having connection with the ignition circuit to render this circuit ineffective when this guarding terminal is connected with said switching mechanism contact by current conducting fluid admitted to the casing.

3. The combination with an ignition circuit for an internal'combustion engine, this circuit containing a source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make said circuit effective and, by their separation, to make said cir- 1o; cuit ineflective; an electrically isolated casing enclosing said switching mechanism, said switching mechanism being provided with lock controlled means for effecting its operation from the exterior of the casing; and a guarding terminal normally having no effective electrical connection within the casing with the contacts of the switching mechanism when the switch is open but ex-- posed for contact with current conducting fluid admitted into the casingto connect it with a contact ,of the switching mechanism, said source of current being included between this contact of the switching mechanism and said guarding terminal whereby 1 current from said source of current is provided with a short circuit when this, con tact of the switching mechanism and said guarding terminal are connected by current conducting fluid admitted to the casing.

4. The combination with an ignition circuit for an internal combustion engine, this circuit containing a source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make said circuit effective and, by their separation, to make said cir'- cuit ineffective; an electrically isolated casing enclosing said switching mechanism, said switching mechanism being provided with lock controlled means for effecting its operationfrom the exterior of the casing; and a guarding terminal normally having no efiective electrical connection within the casing with the contacts of the switching mechanism but exposed for contact with current conducting fluid admitted into the casing to connect it with a contact of the switching mechanism, said source of current being included between this contact ofthe switching mechanism and said guarding terminal whereby current from said source of current is provided with a short circuit when this contact of the switching mocha-- nism and said guarding terminal are con nected by current conducting fluid admitted to the casin 5. The combination with an ignitionbircuit for an internal combustion engine, this circuit containing a source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make said circuit effective and, by their separation, to make said'circuit ineffective; an electrically isolated casing enclosing. said sw itching mechanism, said switching mechanism being provided with lock controlled means for eiiecting its operation. from the exterior of the casing; a guarding terminal normally having no eifective electrical connection within the casing with the contacts of the switching mechanism when the switch is openbut exposed for contact withcurrent conducting fluid admitted into the casingto connect it with a contact of the switching mechanism, said source of current being included between this contact of the switching mechanism and said guarding terminal whereby current from said source ot-current is pro vided with a short circuit when this con tact of theswitchingmechanism and said. guarding terminal are connected by current conducting. fluid admitted to the casing; and means 111 circuit with said guarding terminal and source of current for preventing ,full flow of the current from said source.

6. The combination with an ignition circuit for an internal combustion engine, this circuit containing a source of current; of switching mechanism having contactscontrolling said circuit and serving, by their engagement, to make said circuit efi'ective' and, by their separation, to make said circuit ineffective; an electrically isolated casing enclosing said switching mechanism, said switching mechanism being provided with lock controlled means for effecting its operation from the exterior of the casing;

a guarding terminal normally havingno efmechanism and said guarding terminal are connected by current conduct-ing fluid admitted to the casing; and means in circuit with said guarding terminal and source of current for preventing full flow ot' the current from said source.

7. The combination with an ignition circuit for aninternal combustion engine, this circuit containing a source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make said circuit eflective and, by their separation, to make said circuit ineffective; an electrically isolated casing enclosing said switching mechanism, said switching mechanism be ng provided with lock controlled means for effecting its operation from the exterior of the casing; a guarding terminal normally having no efl'ective electrical connection within the casing with the contacts of the switching mechanism when the switch is open but exposed for contact with current conducting fluid admitted into the casing to connect it with a contact of the switching mechanism, said source of current being included between this contact of the switching mechanism and sa1d guarding terminal whereby current from" said source of current is provided with a short circuit when this contact of the switching mechanism and said guarding terminal are connected by current conducting fluid admitted to the casing; and a fuse in the main circuit of the source of current and adapted to be ruptured upon the establishment of said short circuit,

8. The combination with an ignition circuit for an internal combustion engine, this circuit containing a source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make said circuit effective and, by their separation, to make said circuit ineffective; an electrically isolated casing enclosing said switching mechanism, said switching mechanism being provided with lock controlled means for effecting its operation from the exterior of the casing; aguardwith a contact of the switching mechanism,

ducting fluid admitted to the said sourceof current being included between this contact of the switching mechanism and said guarding terminal whereby current from said source of current is provided with a short circuit when this contact of the switching mechanism and said'guarding terminal are connected by current concasing; and a fuse in the main circuit of the source of current and adapted to be ruptured upon the establishment of said short circuit.

9. The combination with an ignition circuit for an internal combustion engine, this circuit containing a Source of current; of switching mechanism having contacts controlling said circuit and serving, by their engagement, to make-said circuit effective and,

by their separation, to make said circuit in-' efiective; a casing enclosing said switching mechanism, said switching mechanism being provided with'lock controlled means for effecting its operation from the exterior of the casing; a guarding terminal normally having no effective electrical connection within the casing with the contacts of the switching mechanism when the switch is openbut exposed for contact with current conducting. fluid admitted'into the casing to connect it with a contact of the switching mechanism, said source of current being included between this contact of the switching mechaengagement, ,to make said circuit effective and, by their separation, to make said cir cuit ineffective; a v casing enclosing said switching mechanism. said switching mechanism being provided with lock controlled means for-effecting its operation from the exterior of the casing; a guarding terminal, normally having .no effective electrical connection within the casing with the contacts of the switching mechanism but exposed for contact with current conducting fluid admitted into the casing to connect it with a contact of the switching mechanism, said source of current being included between this contact -of the switching mechanism and said guarding terminal whereby current from said source of current is provided with a short circuit when this contact of the switching mechanism and said guarding terminal are connected by current conducting preventing full fluid admitted to the casing; and means in circuit with said guarding terminal and source of current for preventing full flow of the current from said source.

11. The combination with an ignition circuit for an internal combustion engine, this circuit containing a source of current; of

switching mechanism having contacts controlling said circuit and serving, by .their engagement, to make said circuit effective and, by their separation, to make said circuit inetlective; a casing enclosing said switching mechanism, said switching mechanism being provided with lock controlled means for effecting its operation from the exterior of the casing; having no effective electrical connectlon within the casing with the contacts of the switching mechanism when the switch is open but exposed for contact with current conducting fluid admitted into the casing to connect it with a contact of the switching mechanism, said source of current being'ineluded between this contact of the switching mechanism and said guarding terminal whereby current from said source of current is provided with a short circuit when this contact of the switching mechanism and said guarding terminal are connected by current conducting fluid admitted to the casing; and

a. fuse in the main circuit of the source of current and adapted to be ruptured upon the establishment of said short circuit.

12. The combination with an ignition clrcuit for aninternal combustion engine, this circuit containing a source of current; of switching mechanism ha ving contacts controlling said circuit and serving, by their engagement, to make said circuit effective and, by their separation, to make said circuit ineffective; a casing. enclosing said switching mechanism, said switching mechanism being provided with lock controlled means for effecting its operation from the exteriono'f the casing; a guarding terminal normally having no effective electrical connection within the casing with the contacts of the switching mechanism but exposed for contact with current conducting fluid admitted into the casing to connect it with .a contact of the switching mechanism, said source of current being included between this cona guarding terminal normally.

tact of the switching mechanism and said guarding terminal whereby current from said source of current is provided with a short circuit when this contact of the switchmg mechanism and said guarding terminal are connected by current conducting fluid admitted to the casing; and a fuse in the main circuit of the source of current and adapted to be ruptured upon the establishment of said short circuit.

In witness whereof, I hereunto subscribe my name.

GEORGE L. CRAGG. 

